At least eight people have been killed in an explosive fire that destroyed at least 35 boats docked along the Tennessee River in Alabama.

Scottsboro Fire Chief Gene Necklaus said all eight people known to be missing have been confirmed dead, and “that number could go up, because we don’t know how many were on boats” that sank.

The fire began just after midnight at Jackson County Park Marina and quickly consumed the dock as people were sleeping.

The wooden dock went up in flames and an aluminium roof that covered many of the vessels melted and collapsed, cutting off escape routes and raining debris over the area as boaters leapt into the river.

Alabama-Boat Dock Fire
The remains of the dock in Scottsboro (Sierra Phillips/WAAY-TV/AP)

At least seven people were taken to hospital suffering from exposure to the flames or the frigid water.

The fire was spread so rapidly by the wind that “we didn’t have time to do nothing”, said one resident who survived but lost his brother in the water.

Tommy Jones said he was aboard his 35ft cabin cruiser when someone came banging on the boat after midnight saying: “Man, the marina is on fire.”

The flames were racing out to the far end of the dock where his boat was tied. He said he and several other men cut some boats free and sent them drifting out into the water. When a man placed his wife and children in a small boat, they cut that boat free too.

Finally, Mr Jones said, he jumped into the water and swam for shore, 200 yards away. He believes his brother Yancey Roper, who lived aboard another boat, swam in a different direction. Officials later told him his brother had drowned.

He said as he was swimming for shore, “I looked back and that other boat with the wife and the children on it was all engulfed in flames”.

Mr Necklaus said about 35 boats were destroyed, some of them sinking at the dock and others floating away before going under. He said divers need to locate each one and search them individually to be sure there were no other victims.

“We woke up hearing screams and popping noises,” said Mandy Durham, who was with her boyfriend in a nearby boat. “When we woke up, we could see red through the window.”

“Within 15 to 20 minutes, the whole dock was in flames. All these boats have propane tanks and gas tanks, and that’s a lot of fire.”

“There were numerous people rescued from the water who had escaped by going into the water,” Jackson County Chief Sheriff’s Deputy Rocky Harnen said.

Alabama Boat Dock Fire
The charred remains of a boat (Jay Reeves/AP)

People were jumping on to a boat at the end of the dock because fire had consumed the middle portion and that was their only escape, but then the flames spread to that boat, leaving the water as the only way out, Ms Durham said.

Reaching the victims proved challenging for rescue crews.

“The damage from the dock has fallen on top of the boats, and some of the boats have drifted off,” Mr Harnen said.

Hours after sunrise, smoke was still rising from the remains of a wooden dock, and pieces of metal that once formed the roof were partially submerged. Police and fire boats with flashing lights were positioned near the charred remains, and a yellow floating boom was being deployed around the marina to contain spilled fuel.

Most of the boats that were destroyed had people living on them permanently, but some mainly spent weekends on them, Ms Durham said. The park includes a boat ramp, a dock and a restaurant, and offers boat rentals, according to Jackson County’s government website.

“Everybody is just hoping to find the ones they knew on that dock. There were families there. It’s devastating,” Ms Durham said.